Molten metal feeding tube for metal casting machines



April 1961 G. R. MORTON 2,977,649

MOLTEN METAL FEEDING TUBE FOR METAL CASTING MACHINES Filed March 16. 1959 Wil'nai MM United States Paten t' MOLTEN METAL FEEDING TUBE FOR METAL CASTING MACHINES Glen R. Morton, 7025 Sarpy Ave., Omaha, Nebr.

Filed Mar; 16, 1959, Ser. No. 799,558

'4 Claims. (Cl. 22-68) This invention relates to material feeding tubes for casting machines and especially to a molten metal supply tube for metal casting'devices.

Metal casting is an old art. However, modern times require highly eflicient machines that are at least semiautomatic. Electrically controlled fvacuum type machines have solved many problems .present in volume casting. However, much trouble is still experienced in the metal feeding tube or conduit that passes the molten material into the shot cylinder or into the mold cavity. Firstly, the molten metal between intermittent supply flows tends to solidify'onto the walls of the feeding tube. Secondly, the feedingtube transfers objectionable heat to .the shot cylinder and its rampiston.

Thereforeone of the principal objects of my invention is to provide a molten metal feeding tube that prevents the molten material from solidifying onto the walls of the tube and from solidifying .at the communicating orifice of the shot cylinder .01 well.

A further object of this invention isto provide amolten material feeding tube that transfers very little 'heat from the furnace to theshot cylinder ormold.

A still further object of this invention is to provide a molten material feeding tube that eliminates the solidifying of the molten material at the communicating orifice of the-shot well or cylinder therebynot only keeping the orifice open, 'but also permittingthe use of a cooling meansfor the shot well orcylinder and its piston.

A still further object of this invention is to provide a molten material feeding tube that greatly reduces the initial Iimpact shock of the molten material lintermita molten material feeding tube .that is economical in manufacture and durable in use.

These and other objects will be apparent to those skilled in the art.

My invention consists in the construction, arrangements, and combination, of the various parts ofthe device, whereby the objects contemplated are attained as hereinafter more fully set forth, specifically pointed out in my claims, and illustrated in the accompanying drawings, in which:

Fig. l is a longitudinal sectional view of my molten metal feeding tube means detachably secured to a shot cylinder;

Fig. 2 is a top plan view of my device taken from line 22 of Fig. l, and more fully illustrates its construction; and

Fig. 3 is a reduced longitudinal sectional view of a modified form of structure of my feeding tube.

As herebefore indicated, my feeding tube is particularly adapted to modern casting machines such as described in my co-pending application on a Vacuum Casting Machine filed November 4, 1957, and bearing Serial Number 694,315. In most such machines there is a shot cylinder and ram piston for injecting the molten .shot cylinder.

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ma ss into thedie cavity. A material supply'tube'lea'ds with casting machines of the vacuum type, the molten material is sucked through the feeding tube. In fact, with some materials a vacuum machine may dispense entirely with the shot cylinder and connect the feeding tube direct to the mold. In the drawings I show my material feeding tube having its upper end communicating with the inside of a shot cylinder or well 10 and its lower end portion extending into the molten casting material 11 of the furnace. The numeral 12 designates the entrance orifice extending through the wallof the This passageway is tapered as shown in Fig. 1, i.e., its diameter increases as it extends outwardly through-the wall of the cylinder. Embracing this passageway 12 is a resilient gasket 13. The numeral 15 designates a metalthimble in the gasket 13having its outer edge extending laterally. The numeral 16 designates a second resilient gasket on the inner side of the metal thimble 15. The numeral 17 designates a sleeve gasket on the inner side of the gasket 16 having a laterally extending portion .19 under the gasket 16 and a downshould be of a material not capable of being affected by the molten metal. Such material can be silicon carbide or like. The numeral 22 designates my metal feeding tube and its upper end is of a diameter substantially greater than that of the diameter of the skirtportion 20, and engages the underside of the laterally extending portion of the resilient gasket 16. The major portion of the length ofthe tube 22 extends downwardly and laterally from the cylinder 10, and has a'lug 23 on its upper under side. The numeral 25 designates an ordinary .C-clamp having its cap screw '26 engaging the 7 top of the cylinder 10 and its lower end detachably hooked over thelug 23. By this arrangement the material feeding tube unit is detachably secured to the shot cylinder. tact the .metal shaft cylinder, the metal thimble or .the

The metal ofthe tube does not directly .con'

metal gasket.

I insulate both the inside and outside of the metal tube 22. Any suitable insulation material not affected by the molten casting material may be used, such as silica or like. In Fig. 1 I show such insulation 27 on the inner wall side of the tube 22. This insulation 27 extends upwardly to embrace the outside of the skirt portion 20 and to engage the underside of the gasket 16 as shown in Fig. 1. This insulation has a bore 29 decreasing in diameter as it extends upwardly and then terminates in a large cavity 30 communicating with the under open end of the gasket 17. In Fig. 3 I show this insulation on the inner side of the tube in the form of a vacuum compartment 31 formed by the sleeve 32 and the inside of the wall of the tube. On the outer side of the tube I embrace the same with insulation 35. By this arrangement of parts the metal tube will not become excessively hot and furthermore, it will not unduly transfer heat to the shot cylinder. Also the molten material will not become chilled to such an extent that it will solidify on the innerside of the feeding tube unit. Also because of the gaskets and thimble, the molten metal that drains back from the orifice of the cylinder cannot contact the hold cylinder at this point and therefore will not congeal and close the passageway.

With the thermal tube design and the double insulated connection to the shot well, it is possible and practical to feed molten metal from the center of the bath to the shot well with no thought of solidification, even when started from cold. It takes about one hour for the thermal tube to come up to heat on the inside but it need never be removed once it is installed as the highly insulating material is not affected by the molten metal. Ordinarily the metal travels up the tube slowly and at a constant speed, but with the orifice up to the top out of the bath the metal travels at a terrific speed until it hits the restricted orifice and the sudden stopping of the metal is like a hammer blow. This would obviously ruin the insulation, but by tapering this hole from large at the bottom to small at the top, this impact is reduced to the degree that this material will stand up. This also explains to a degree why the bath level does not affect the size of the shot since the time element for the metal to reach the orifice is so short it is negligible. Furthermore, by my construction there will be little undesirable turbulence inside the shot chamber of the cylinder. Also any metal that might have slightly solidified on the reverse taper of the gasket sleeve will be free to go into the shot cylinder with the next casting.

Some changes may be made in the construction and arrangement of my molten metal feeding tube for metal casting machines without departing from the real spirit I and purpose of my invention, and it is my intention to cover by my claims, any modified forms of structure or -use of mechanical equivalents which may be reasonably included within their scope.

I claim:

1. A molten metal feeding tube for use in feeding molten metal from a molten-metal supply reservoir to a shot cylinder of a molding machine having an opening in one wall thereof, said molten metal feeding tube comprising an elongated hollow-sleeve frame having a first end, insulating means extending through the entire inside of said sleeve frame and covering the major portion of the outside of said sleeve frame, said insulating means defining an insulated passageway inside said sleeve frame, extending therethrough, and terminating in an outlet well having a substantially larger cross-section than the end of said passageway communicating therewith, said well being disposed adjacent said first end of said sleeve frame, said well having an outlet end aligned with said first end of said sleeve frame, a tapered feed sleeve extending into the opening in the wall of the shot cylinder and disposed concentrically with and in communication with said outlet well, the common axis of the outlet well and tapered feed sleeve being disposed at an acute angle with respect to the longitudinal axis of the sleeve frame, a gasket means surrounding said feed sleeve and insulating said feed sleeve and said sleeve frame from the wall of the shot cylinder, and means for securing said tube to said shot cylinder.

2. A molten metal feeding tube as defined in claim 1 wherein said insulating means comprises an enclosed vacuum extending through the entire inside of said sleeve frame, and a solid insulating material covering the major portion of the outside of said sleeve frame.

3. A molten metal feeding tube as defined in claim 1 wherein said sleeve frame has a lug projecting outwardly therefrom in spaced relation to said first end of said sleeve frame, and wherein said means for securing said tube to said shot cylinder cooperates with said lug.

4. A molten metal feeding tube for use in feeding molten metal from a molten-metal supply reservoir to a shot cylinder of a molding machine having an opening in one wall thereof, said molten metal feeding tube comprising an elongated hollow-sleeve frame having a first end, an insulating member extending through and engaging the entire inside of said sleeve frame and covering the major portion of the outside of said sleeve frame including the end of said sleeve frame opposite said first end, said insulating member having an internal bore extending therethrough, and terminating in an outlet well having a substantially larger cross-section than the end of said bore communicating therewith, said well being disposed adjacent said first end of said sleeve frame, said well having an outlet end aligned with said first end of said sleeve frame, said bore increasing in cross-section as the distance from said outlet well increases, a tapered feed sleeve extending into the opening in the wall of the shot cylinder and disposed concentrically with and in communication with said outlet well, the common axis of the outlet well and tapered feed sleeve being disposed at an acute angle with respect to the longitudinal axis of the sleeve frame, a gasket means surrounding said feed sleeve and insulating said feed sleeve and said sleeve frame from the wall of the shot cylinder, and means for securing said tube to said shot cylinder.

References Cited in the file of this patent UNITED STATES PATENTS 1,473,246 Montupet Nov. 6, 1923 1,965,340 Heinicke July 3, 1934 2,058,378 Freund Oct. 20, 1936 2,671,936 Sundwick Mar. 16, 1954 2,817,884 Ring Dec. 31, 1957 2,852,822 Strom Sept. 23, 1958 2,864,140 Morgenstern Dec. 16, 1958 

